Device for adjusting the stroke force of the type bars in power-driven typewriters, bookkeeping machines and the like



Aug. 18, 1959 B. NITSCHKE 2,900,062

DEVICE FOR ADJUSTING THE STROKE FORCE OF THE TYPE BARS IN POWER-DRIVENTYPEWRITERS, BOOKKEEPING MACHINES AND THE LIKE Filed April 10, 1957 3Sheets-Sheet 1 FIG- 7 Watson Cole G-v mcne WSCsoh HUB/ways Aug. 18, 1959B. NITSCHKE 2,900,062

DEVICE FOR ADJUSTING THE STROKE FORCE OF THE TYPE BARS IN POWER-DRIVENTYPEWRITERS, BOOKKEEPING MACHINES AND THE LIKE Filed April 10. 1957 3Sheets-Sheet 2 flwlvo A isc Ma WaiSQM Co a, Qw nJ/e WAT/3D! Aug. 18,1959 B. NITSCHKE 2,900,062

DEVICE FOR ADJUSTING THE STROKE FORCE OF THE TYPE BARS IN POWER-DRIVENTYPEWRITERS, BOOKKEEPING MACHINES AND THE LIKE Filed April 10, 1957 3Sheets-Sheet 3 wmwra .Brwro Mf /4k, wgtsav Cole, Crrlwdle WiBQo'w UnitedStates Patent DEVICE FOR ADJUSTING THE STROKE FORCE QF .THE TYPE BARS INPOWER-DRIVEN TYPE- WRITERS, BOOKKEEPING MACHINES AND THE LIKE BriiiioNitschke, Frankfurt am Main. German assignor to Adler'werke vonn.Heiin'ich Kleyer Aktiengesellschaft Application April 10, 1957, SerialNo. 651,946 Claims priority, application Germany April 14, 1956 12Claims. (Cl. 197-17 invention relates to a mechanism for regulatingfbrce' of the stroke of type bars of power driven typewriters,bookkeeping machines and the like. it an object of the invention toprovide each type bar operating mechanism with a contact portion whichcooperates with a driving cylinder and with a counter stop which isoperative just before the striking of the type head. Another object dotthe invention resides in amechanism in which the abutting surface ofeach striking inember is adjustable by means of a screw in order toadjust each type very accurately as to the force of the impact; It isalso an object of they invention to adjust the force of the stroke of aplurality or all of the type bars and to adjust the type bars of thecapital letters as well as the small letters and the various numbersand; punctuation marks; Further objects will be apparent from thefollowing description when considered in connection with theaccompanying drawings in which:

. Figure 1 is a side elevation partly in section of the type baractuating mechanism,-

Fig. '2 is the detail of the actuator on an enlarged scale,

Fig. 3 is' a side elevation similar to Fig. 1 showing atype bar justbefore striking the platen,

swung or rotated clockwise around the pivot 13. As a; result of therotation of the arm 11a, the lever 8 will be rotated clockwise aroundits pivot 16 against the tension of a spring 17. Thereby a tension rod20 connected to the upper end of the driving lever 8, will be pulled tothe right, Fig. 3, so that the type lever 19' will be raised in knownmanner, so that the type head 13 will be struck against a sheet of paperon the platen 21. Upon the swinging of the driving lever 8, the upperbent-over edge of the link 6 will slide off the lower edge of theprojection S of the type lever 5. The link 5 will thus be swung by thespring 7 until it abuts with its bent-over part on the lower edge of aprojection 85, Fig. 4. According to the invention an abutmentorimpacting part 23 is adjustably mounted on the arm 11a which abutsagainst a counter stop 24a of a stop rod 24' shortly before the typehead 18 strikes the platen. Hereby upon further swinging of the drivelever 8 due to its inertia, the friction surface 14 of the contactportion 11 will be lifted from the drive cylinder 15. After such liftingaction of the drive connection, the contact portion 11 will be swungcounterclockwise by its spring 12 around its pivot 13 until it strikesagainst a stop 26 on the lever 8 by means its edge portion 25.

After the type head 18 has struck the platen 21, the;

I lever 8 will return to its initial position by means of the spring 17as shown in Fig. 1, the lever 8 by its projecting edge 22 striking astop abutment 27. The link 6 will at the same time rest again under theprojecting member 5 of the key lever 2 as soon as the key 1 Fig. 4 isaside view of a detail showing the actu- 1 in the direction of thearrows.

Fig. 1 shows the various parts in the position of rest andas shown eachtype key 1 is mounted on its type lever 2 with a spring 3 connected tonormally force the type lever againsta common stop bar 28; If the typehey I is depressed from its initial position, Fig. 1, the lever 2 willpivot around its bearing pin or position 4 with the lever movingclockwise. This will result in a projecting member 5 of the key lever 2contacting and depressing a link 6 to pivot around a pin 9 against theaction of a spring 7, the in 9' bein mounted and secured on an actuatinglever 8 and projecting into a slot 29 in the link 6. Due to thismovement, the link 6 will press on a projection 10 of an arm 11a havinga contact portion 11 with the latter being connected'by a' tensionspring 12 with the lever 8; The arm 11a is pivotally mounted on thelever 8 by a pin 13. As in Fig. 3 the friction su'rface' 14 of thecontact po'iti ciii 11" will thus engage the drivin rolli 15 to beaii-iaid thefe b y. i

The frictionsurface 14 and the projection 11 may be advantageously madeof a synthetic or artificial material which may be sprayed an a metallicbase of the arm 11a, is siidwri in Fig. 2; whereby by depressions andholes the r'rietallicba'se to provide a secure connection. The contactpdrtiotrH will be carried along the rotating drive cylinder 15' and theaim 11a will be is released; If, however, the key 1 is still depressed,then a repeated stroke of the type bar will be avoided in that the link6 upon the return swing of the driving lever 8 to the left will resultin the edge 6a, Fig fi, abutting against the edge 5a of the projection 5of the key lever 2 during the further left movement of the driving lever8 so that the spring '7 will be tensioned and the pin 9 will slide inthe slot 29. The projection 5 of the key lever 2, which has beendepressed, cannot cooperate with the link 6. After the key 1 isreleased, the projection 5 of the lever 2 will move upwardly so that thelink 6, under the pull of the spring '7, will slide along the projection8a until it is again under the projection 5 of the key lever 2 in theinitial position according to Fig. 1. i

The abutment part 23 is provided adjustably on the arm 11a of thecontact portion 11 and in the structure disclosed in Fig. 2 the abutmentpart 23 is slidable on the guide 38 of the contact portion 11. The part23 can be accurately adjusted by a screw 36 and can be held in suchadjusted position and the screw 30 grips in a nut 31 which is set in thearm 11a of the contact portion 11. The abutment part 23, which may bemade of an artificial or synthetic material, grips in the ring nut 32 ofthe screw 3i) so that it may rotate in the part 23, but is not slidablymounted. I

If the abutment or impacting part 23 is moved in the direction of thearrow 33, Fig. 2, then the abutment surface 23a will contact the counterabutment 240 through a smaller rotary angle of the contact portion 11relative to the initial position according to Fig; 1. This results inthe type striking mechanism following a shorter path initiated by thedriving cylinder and thereby the force stroke is diminished. Uponcounter rotation of the screw 30, the part 23 will be moved in directionopposite the direction of the arrow 33 whereby the contact portion 11will move through a larger angle from the initial position of Fig. 1 tothe abutting position of the surface 23a against the counter abutment24a.

- The abutting surface 23a of the part 23 which during typing abutsagainst the counter surface 24a of the rod 24, is arranged at a sharpangle relative to the guide 38. Hereby it will be possible to accuratelyset the impacting position of the part 23 and thus the portion 11 isadjusted by the screw 30.

The abutting surface 23a is further arranged in such a way that thepivot 13 of the portion 11 is below the extension of the surface 23a.Thus the impact part 23, Fig. 3, in the abutting position, will have asofter contact with the counter abutment 24a since due to theflexibility of the impact part 23 which is made of an artificial orsynthetic material, and due to the angular position of the impactsurface 24a, a sliding action, even if slight, will produce a smallsliding action between the impact surface 23a and the counter impactsurface 24a. Thereby the usual noise and vibrations will be avoided orat least greatly reduced.

The arrangement of the impact part 23 on the arm 11a of the portion 11relative to the counter abutment 24a on the rod 24 is of necessity soprovided that in the impact position according to Fig. 4, the reactionof the impact force on the surface 23a is directed in the direction ofthe further movement of the pin 13 of driving lever 8. Upon impact animpulse from the counter abutment 24a on the impact part 23 willtherefore be absorbed in the sense of a further movement of the drivinglever 8. Thereby the free further movement of the type impact mechanismafter the completion of the driving connection between the drivingcylinder 15 and the contact portion 11 will cease.

The counter abutments 24a for a plurality of type impact members 8, 20,19 are preferably arranged on a common rod 24. Hereby the structure willbe considerably simplified. The rod 24 is therefore adjustable so thatthe distance of the counter abutment 24a from the impact surface 23awill be regulated. The adjustment of the distance is accomplished insuch a way that the portion 11 may be rotated through a larger orsmaller angle until it will assume the initial position according toFig. 1. Thus the impact force for all the type mechanisms 8, 20, 19 maybe regulated together to agree with the total forces or the desiredpressure force.

For this purpose the rod 24 is mounted on two links 35, one only beingshown in Fig. l, pivotally mounted on a bearing 36. In order to adjustthe rod 24 there is mounted in the frame of the machine, preferablywhere it can be easily reached, a setting member 39, Fig. 5, which asshown is in the form of a setting segment which may be provided in itsperiphery with teeth, for example i rality of ratchet teeth 47 thereonwhich cooperate with a ratchet link 46 which latter is under theinfluence of a spring to force the ratchet 46 against the teeth 47where- 'by the respective setting o-f-the wheel 39 will be maintained. Acrank arm or lever 44 is connected to the crank arm or lever 43 and thislever 44 pivots on a pin 45. On one arm of the crank arm 44 there issecured a pin 48 on which a link 49 is mounted at one end with the otherend secured to two links 50 and 51 rigidly secured to each other. Thelink 51 is connected to the rod 24 so that by rotation of the settingmember 39 the rod 24 will be swung around the bearing 36. By adjustingthe member 39, the rod 24 may be 'set for' a greater or smaller distanceof the impact part 23 and thus the impact force for all the type barswill be regulated as a whole.

YFor further regulation of the impact force, the rod 24 is adjustablewhen changing from small letters to capitals or from capital letters tosmall letters. Thereby the impact force is automatically increased whenchanging from small letters to capital letters since the capital lettershave a larger printing surface to attain a uniform typing. According toFig. 5 upon adjustment, an eccentric disc 54 is coupled with a driveshaft 55 whereby by means of rollers 56 and 57, a control lever 58 isadjusted around its bearing point 59. By means of link 60 connected'tothe control lever 58, the type lever segment will be brought to itslower or starting point. The con-' trol lever 58 grips with one arm 62an extended arm 52 which is rotatable around its bearing point 63 and anarm is connected at 53 to the link 50. Therefore, upon adjustment thecontrol lever 58 will be swung clockwise around the bearing point 59 andthe arm 52 will swing counterclockwise around its bearing point 63.Thereby the linkage 49, 51 will be raised through the link 50 and therod 24 will be moved downwardly. Thus the impact force of the type headswill be increased.

I claim as my invention:

l. Mechanism for regulating the striking force of the type heads ofpower-driven typewriters, bookkeeping machines and the like comprisingan actuating lever pivotally connected to a frame of the typewriter andprovided for each key lever, a contact portion pivotally mounted on theactuating lever, an impacting part on said contact: portion and havingan impacting surface, and means for adjustably mounting the impactingpart.

2. Mechanism according to claim 1, in which the contact portion isprovided with a guide on which the impacting part is adjustably mounted.

3. Mechanism according to claim 1, in which the contact portion isprovided with a guide on which the impacting part is adjustably mounted,and in which the means for adjusting the impacting part comprises ascrew member. 4. Mechanism according to claim 1, in which the contactportion is provided with a guide on which the impacting part isadjustably mounted, the impacting part being composed of a syntheticmaterial.

5. Mechanism according to claim 1, in which the contact portion isprovided with a guide on which the impacting part is adjustably mounted,said impacting surface forming an acute angle relative to the guide.

6. Mechanism according to claim 1, in which the contact portion isprovided with a guide on which the impacting part is adjustably mounted,said impacting surface being provided below an extension of the contactportion.

7. Mechanism according to claim 1, in which a rod is provided mountedbelow the impacting part to form an abutting member for the impactingsurface of the impacting parts.

8. Mechanism according to claim 1, in which a rod is provided mountedbelow the impacting part to form an abutting member for the impactingsurface of all the impacting parts, and in which means are provided tomount the rod so that it may be regulated as to its initial distancefrom the impacting surface.

9. Mechanism according to claim 1, in which a rod is provided mountedbelow the impacting part to form an abutting member for the impactingsurface of all the impacting parts, and in which means are provided tomount the rod so that it may be regulated as to its initial distancefrom the impacting surface, said pivotal mounting of the actuating leverand the impacting part determining the direction of movement of theimpacting surface.

10. Mechanism according to claim 1, in which a rod is provided mountedbelow the impacting part to form an abutting member for the impactingsurface of all the impacting parts, and in which links are provided tosupport the rod.

11. Mechanism according to claim 1, in which a rod is provided mountedbelow the impacting part to form an abutting member for the impactingsurface of all the impacting parts, and in which links are provided tosupport the rod and means are provided to adjust the links and rodrelative to the impacting part.

12. Mechanism according to claim 1, in which a rod is provided mountedbelow the impacting part to form an abutting member for the impactingsurface of all the impacting parts, and in Which means are provided foradjusting said rod to increase the type head typing force for capitalletters as compared with the typing force for small letters. 1

References Cited in the file of this patent UNITED STATES PATENTS

